3 lights

Hi reefers! I have 1 Ai 64 hydra hd + 1 red sea 90 light for my red sea 170 tank. Im planning to get another red sea 90 lights just to make the spectrum balance for my red sea 170 (60 x 50 x 50) tank. Do you think this light is overkill if I adjust all the spectrum by half? Limiting the...